Usually, optical elements such as camera lenses and spectacles are in used in cylindrical form. However, original optical workpieces (i.e. lens blanks) are most easily manufactured in the form of a square. Therefore, these original optical workpieces have to be cylindrically ground before use.
A typical example of a contemporary cylindrical grinding apparatus is a centraling apparatus. The centraling apparatus typically includes a pair of holders for holding the original workpiece, where each holder has a hollow chamber communicating with a surface of the holder. The holder can hold the workpiece on its surface by using an air pump creating suction in the hollow chamber, a grinding wheel is then used to cylindrically grind the workpiece. However, the centraling apparatus can only cylindrically grind one workpiece at a time.
FIG. 2 shows a method for cylindrically grinding more than one workpiece 50 at a time. The workpieces 50 are bonded together using ultraviolet adhesive. Then a grinding wheel 40 is used to grind the bonded workpieces 50 into a cylindrical shape. During the grinding process, the grinding wheel grinds the bonded workpieces 50 along an X direction and a Z direction. However, when grinding along the X direction, the grinding wheel needs to run along the X direction many times because the grinding wheel only contacts the workpieces over a small area.
Therefore, a method for cylindrically grinding workpieces which can overcome the above-described problems is desired.